SQL & PL/SQL :: Unable To Add Columns With Default Value Due To Compression

We are trying to add 2 columns in a partitioned table.but we are getting below error:

SQL Error: ORA-39726: unsupported add/drop column operation on compressed tables

But, it is not a compressed table.

select table_name, compression from user_tables
where table_name ='SVC_ORDER_CODE_FACT'

TABLE_NAME COMPRESSION
------------------------------ -----------
SVC_ORDER_CODE_FACT

actually we are trying to add 2 columns as below:

ALTER TABLE SVC_ORDER_CODE_FACT
ADD (MKT_FEATURE_KEY NUMBER default '-2', PREV_MKT_FEATURE_KEY NUMBER default '-2');

But, if we add column without default value,